The mammalian sex chromosomes are thought to be related to each other by sharing a common origin. That is, the X and Y chromosomes originally evolved from a pair of chromosomes that only differed at the locus determining sexual differentiation. For example, this evolutionary relationship is reflected during meiosis in chromosomal pairing between the tip of the human X chromosome short arm and the Y chromosome which presumably implies sequence homology. However, compelling genetic evidence for functional homology between the mammalian X and Y chromosome is lacking. We describe here the localization of a gene to the tip of the short arm of the human X chromosome and evidence for a related gene on the Y chromosome.

Alleles↗

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Chromosome 5 allele loss in human colorectal carcinomas.

That the sporadic and inherited forms of a particular cancer could both result from mutations in the same gene was first proposed by Knudson. He further proposed that these mutations act recessively at the cellular level, and that both copies of the gene must be lost for the cancer to develop. In sporadic cases both events occur somatically whereas in dominant familial cases susceptibility is inherited through a germline mutation and the cancer develops after a somatic change in the homologous allele. This model has since been substantiated in the case of retinoblastoma, Wilms tumour, acoustic neuroma and several other tumours, in which loss of heterozygosity was shown in tumour material compared to normal tissue from the same patient. The dominantly inherited disorder, familial adenomatous polyposis (FAP, also called familial polyposis coli), which gives rise to multiple adenomatous polyps in the colon that have a relatively high probability of progressing to a malignant adenocarcinoma, provides a basis for studying recessive genes in the far more common colorectal carcinomas using this approach. Following a clue as to the location of the FAP gene given by a case report of an individual with an interstitial deletion of chromosome 5q, who had FAP and multiple developmental abnormalities, we have examined sporadic colorectal adenocarcinomas for loss of alleles on chromosome 5. Using a highly polymorphic 'minisatellite' probe which maps to chromosome 5q we have shown that at least 20% of this highly heterogeneous set of tumours lose one of the alleles present in matched normal tissue. This parallels the assignment of the FAP gene to chromosome 5 (see accompanying paper) and suggests that becoming recessive for this gene may be a critical step in the progression of a relatively high proportion of colorectal cancers.

Adenocarcinoma↗

PubMedDate not supplied

Relative and absolute changes of activated platelets, microparticles and platelet aggregates after activation in vitro.

Standard flow cytometers provide relative numbers of activated platelets, microparticles, and platelet aggregates. With fluorescent beads it is now possible to determine absolute numbers. Whole blood and platelet-rich plasma were incubated with agonists (ADP, collagen, thrombin). CD62p expression, microparticle and platelet aggregate formation were measured. Flow-Count Fluorospheres((R)) were added to calculate absolute concentrations. After activation there was an increase in the percentage of CD62p-positive platelets. However, the total number of platelets decreased and therefore the absolute number of CD62p-positive platelets did not increase but decreased. The number of CD62p-positive platelets decreased not as much as the number of CD62p-negative platelets, which explains why the relative percentage of CD62p-positive platelets increased. A similar increase in percent and decrease in absolute counts was found for microparticles. Platelet aggregates increased both in relative and absolute numbers. These results suggest that the detection of activated platelets by flow cytometry has to be complemented by the determination of the absolute concentrations to avoid misinterpretation.

Blood Platelets↗

PubMedDate not supplied

Comparison of beta-thromboglobulin, flow cytometry, and platelet aggregometry to study platelet activation.

This study compares granule membrane protein (GMP)-140 expression measured by flow cytometry, release of beta-thromboglobulin (beta-TG), and platelet aggregometry as markers of platelet activation in vitro. Whole blood was activated with different concentrations of thrombin. There was a significant increase in beta-TG plasma levels after stimulation with 0.01 and 0.04 U thrombin/ml. There was also an increase in GMP-140 expression, but interindividual variability was high. Aggregometry of platelet-rich plasma did not detect platelet activation and formation of platelet aggregates with 0.05 and 0.1 U thrombin/ml, while flow cytometry showed an early and significant increase of GMP-140 expression with these doses. Beta-TG release is a more sensitive marker of platelet activation than GMP-140 while flow cytometry is easier to perform and less susceptible to artifacts.

Anticoagulants↗

PubMedDate not supplied

Sinonasal cancer and exposure to softwood.

In order to study the connection between occupation and sinonasal cancer we have reviewed the files and histological sections of 70 patients (24 females and 46 males) treated at the Department of Oto-rhino-laryngology, National Hospital of Norway. Detailed information concerning previous occupations was obtained by telephone interviews according to a standardized questionnaire. This pilot study revealed a strong association between wood dust exposure and sinonasal cancer. Of 12 wood dust exposed men, 11 had been exposed exclusively to softwood. While squamous cell carcinoma was the predominant type of cancer in joiners, carpenters and loggers, non-Hodgkin lymphomas appeared to be associated with employment in saw- and planingmill firms. A nationwide case-control study is under preparation for further substantiation of the health hazards connected with exposure to softwood and other possible occupational factors related to sinonasal cancer.

Adenocarcinoma↗

PubMedDate not supplied

The nasal mucosa in softwood exposed furniture workers.

Recent reports suggest that softwood exposed woodworkers may have an increased incidence of sinonasal carcinoma. The present study was undertaken in order to evaluate the histological changes, especially the presence of possible precancerous lesions, in the nasal mucosa of furniture workers exclusively exposed to softwood. Histological examination of nasal biopsies from 44 furniture workers and 37 controls revealed a higher degree of metaplastic changes in the former group. In addition we observed four cases (9%) of dysplasia among softwood exposed workers. Nasal epithelial dysplasia is morphologically similar to dysplasia in other organs where the precancerous state of this lesion has been proved. Acceptance of nasal dysplasia as a precancerous lesion means that histological examination of biopsies is an appropriate tool in identifying occupational groups with an increased incidence of sinonasal carcinoma.

Adult↗

PubMedDate not supplied

Development of brush cytology for detection of metaplastic and dysplastic nasal mucosa lesions. A preliminary report.

Nickel workers and wood workers have an increased incidence of carcinoma and of lesions of the nasal mucosa regarded as precancerous, i.e. dysplasia. This preliminary study demonstrates how metaplastic and dysplastic changes of the nasal epithelium may be diagnosed independently from cytological smears and from histological sections of samples from the same middle nasal turbinate. The sampling technique described yielded excellent material for cytological diagnosis and was also suitable for detailed cell surface characterization by scanning electron microscopy (SEM). Exfoliative cytology was found to be a reliable means of detecting preneoplastic changes in the nasal mucosa of individuals in selected risk groups. The sampling procedure causes less discomfort to the subjects and requires fewer resources than biopsy procedures.

Biopsy↗

PubMedDate not supplied

Evaluation of the VIDAS Listeria (LIS) immunoassay for the detection of Listeria in foods using demi-Fraser and Fraser enrichment broths, as modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06).

A multilaboratory study was conducted to compare the VIDAS LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types--brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef--at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.

Animals↗

PubMedDate not supplied

The Philadelphia chromosome in two children with chronic myeloid leukemia.

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Child↗

PubMedDate not supplied

Mucocutaneous pigmentation and intestinal polyposis (Peutz-Jeghers syndrome) in a family of Iraqi jews with polycystic kidney disease. With a chromosome study.

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Adolescent↗

PubMedDate not supplied

XX/XY lymphoid chimerism in a boy with fatal lymphohistiocytic proliferation.

XX/XY chimerism, present in peripheral blood and bone marrow cells, but absent in other somatic tissues, was demonstrated in a 6-year-old patient. The initial clinical presentation with "butterfly" rash, pancytopenia with a hemolytic component, and hypergammaglobulinemia was suggestive of an immune disorder. Infiltration of skin, bone marrow, and lymph nodes with histiocytes, without disruption of the general configuration, was similar to the findings in familial lymphohistiocytosis. The results of specific cellular markers and of cytogenetic and immunologic studies are analyzed and the nature of the disease and origin of the chimeric state are discussed. The most likely explanations include a chronic graft-vs-host reaction induced by proliferation of foreign lymphoid cells derived from a blood transfusion that the child had received during infancy, or proliferation of neoplastic cells present in the transfused blood.

Child↗